textproduct: Quad Cities

KEY MESSAGES

- Back to back Enhanced Risk/Level 3 severe weather days Today and Friday with all severe hazards possible.

- Very fast storm motions to 60 mph with any storms this afternoon will offer significantly less time to act, thus it's very important to stay weather aware!

- Away from the storms, it will turn windy this afternoon with advisory criteria southerly winds gusting to around 45 mph for areas, mainly south of Hwy 30. - Several more rounds of showers and storms to go through over the next 48 hours, leading to widespread soaking rains of 1-4+ inches.

SHORT TERM /THROUGH TONIGHT/

Issued at 355 AM CDT Thu Apr 2 2026

It's a soggy early morning throughout the region with strong elevated warm, moist advection aided by a 50 kt LLJ atop a stationary boundary near the I-70 corridor. PWATs are surging to near 1.4-1.5 inches and additional synoptic scale ascent aided by a weak coupling of upper jets is leading to a large area of rain, moderate to locally heavy at times with isolated embedded thunder. These processes will persist into mid-morning before gradually weakening, which should foster some decaying of precipitation coverage mid-late morning, as the front lifts back northward as a warm front and begins to lift across the area ahead of a surface low moving into southwest/south central Iowa by 18z. That being said, we're not expecting to see a clear radar scope at any time today, and to that point there is growing consensus in the CAM guidance of another burgeoning round of precipitation toward midday through mid afternoon. This looks to be our first potential window (roughly noon to 4 PM) for severe weather aided by a 500 hPa speed max. This is lower confidence, but will have to keep a close watch for any of this convection trying to become more rooted along the instability axis near the lifting warm front. Should any storms become surface based there will be a threat for a tornado and damaging winds.

The period of greatest concern for severe weather appears to be focused roughly around 4 PM to 8 PM, ahead of the surface low (as it lifts into southern Wisconsin) and an attendant cold front. This low track coupled with a negative tilt shortwave and a cyclonically curved 500 hPa jet and 50+ kt LLJ conceptually pose a favorable severe weather setup for the area. Mesoscale kinematic and thermodynamic environment depicts instability or CAPE of roughly 1000-1500+ j/kg with bulk shear of 40-50 kts. Deep layer shear vectors are oriented more perpendicular to the initiating boundary /cold front to where discrete cells would look to be favored initially. All hazards are in play, although the primary risks look to be damaging winds given magnitude of shear and also a few tornadoes given the curvature in the hodographs. 0-1 km shear is upwards of 35-40 kt, which is very close to the threshold for near certainty of tornadoes (>40 kt) in the presence of severe convection. The tornado concerns may be maximized along and northwest of a line from Washington, Iowa to Quad Cities to Freeport, Illinois. This quadrant will be close to the passing vort max and be more favored for some slight low level backing of winds, which if occurs would enhance the 0-1/0-3km SRH with some guidance indicating values over 200 m2/s2. An Enhanced Risk or level 3 of 5 risk remains in place for much of the area.

Storm motions this afternoon/early evening will be extremely fast at around 60 mph! This will greatly reduce your time to take action, thus it's recommended to plan ahead on where you will go to seek shelter and don't wait until the warning is issued. Stay weather aware!

As often the case with severe weather setups there does exist some uncertainty and potential failure modes. Uncertainty exists with the extent of recovery or destabilization amidst the extensive rain and clouds this morning. If we stay cloudy and keep more precipitation around longer than expected leading to cooler temperatures then this could impact updraft strength. In addition, there is quite a bit of environmental shear and could there be too much to which if the case could disrupt updrafts (more heavily sheared), and hence hinder the strength and sustenance of storms. It will be a day of heavy mesoscale forecasting!

One final thing, outside of any storms we'll see windy conditions develop by afternoon in a strengthening low level pressure gradient and with additional assist of mixing of stronger winds to the surface. Much of the CAM guidance, forecast soundings and HREF ensemble mean gusts and probabilistic wind guidance (60-80% probabilities for winds greater than 40 mph) suggest the likelihood of low end wind advisory criteria, mainly south of an Iowa City to Clinton line this afternoon.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 355 AM CDT Thu Apr 2 2026

The pattern remains quite active Friday into early Saturday, as another trough over the western CONUS ejects eastward, albeit larger and deeper/stronger as it tracks across the Upper Midwest. There are some similar aspects to the Thursday system, but a later time of day and bit further west mass field placement continues to favor the strongest storm initiation off to the west of the service area late Friday afternoon/early evening. This has the potential to evolve into a mature squall line or QLCS and move across the area during the evening, exiting in the early overnight. Timing of severe weather would be roughly 7 PM to 1 AM. But, will have to keep tabs on the potential for some discrete supercell potential particularly south of I-80 near the warm front. This setup looks to largely favor damaging winds with some significant wind potential, and a few tornadoes with any mesovortices. The prime warm moist conveyor fueling a swath of heavy rain may look to occur just to the south and southeast of the service area Friday night into Saturday. The fast motion of the line would likely limit flash flooding concerns. Overall, these few rounds of rain Thursday and Friday night combined with rain that has already occurred in the past couple of days will lead to widespread soaking rain totals of 1-4 inches by Saturday morning. Isolated higher amounts of 5-6 inches can't be ruled out. This will be mostly beneficial and not cause too much in the way of flooding concerns with mostly within bank rises on rivers, albeit significant unless a river basin does manage to get picked on with repeated rounds of heavy rain in which case would pose a flood threat. Flash flooding threat appears low as well, with the main focus being urban areas with any high rainfall rates.

Saturday will see conditions begin to dry out and turn cooler as high pressure begins to build in.

Sunday through Tuesday...Continued cooler and more seasonable this stretch into early next week, with a return flow induced precip event possible some time Tue into next Wed.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 546 AM CDT Thu Apr 2 2026

IFR to LIFR conditions are expected through this morning in low clouds, fog, and showers/isolated storms ahead of a lifting warm front. A strengthening LLJ will continue to foster LLWS through 16z. This afternoon into very early evening (19z-00z) there is the potential for a couple of rounds of storms ahead of a low pressure system and cold front. A few of the storms may be severe with all hazards possible. Have handled the storm potential with a PROB30 or TEMPO mention. Winds will turn from easterly to southerly by this afternoon. Strong southerly winds ahead of the storms will gust 30-40 kt, and any storms will have the ability to mix down stronger winds to around severe criteria (50 kt). Conditions this afternoon should improve to MVFR and VFR predominantly with some IFR (visibility) possible in storms. Winds will veer W/SW and remain gusty this evening/night up to 30 kt and some wrap-around low clouds and MVFR ceilings will be favored north of I-80 mainly.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Wind Advisory from 1 PM this afternoon to 7 PM CDT this evening for IAZ067-068-078-087>089-098-099. IL...Wind Advisory from 1 PM this afternoon to 7 PM CDT this evening for ILZ009-015>018-024>026-034-035. MO...Wind Advisory from 1 PM this afternoon to 7 PM CDT this evening for MOZ009-010.